Weak acid–base interaction induced assembly for the formation of berry-like polystyrene/SiO2 composite particles

To investigate the formation mechanism of berry-like polystyrene/silica (PS/SiO2) with carboxyl-functional templates through in-situ sol–gel process, different alkalis were adopted to catalyze the hydrolysis reaction of tetraethoxysilane (TEOS) and the morphology of composite particles was observed by TEM. The results showed that the weak acid–base interaction (–COO−/–N+/–SiO−) drove the silica particle nucleated and growth on the surface of PS spheres and berry-like structure can be easily adjusted by alkalis and volume ratio of ethanol/water. The present work implied that the weak acid–base interaction can be used to control the nano/micro or hierarchically structures. In addition, the particulate films were constructed by assembling these berry-like particles on the glass substrates. After surface modification with dodecyltrichlorosilane, hydrophobic surface can be obtained and the contact angle of water on the dual-sized structured surface can be adjusted.